Post swift error with alamofire

But once I come to ask for help from you. I'm developing an application in Swift using web service writing in java hosted at Amazon AWS.

When I try to make a registration via post the registration is not performed. The error that returns me is as follows

  FAILURE: Error Domain=NSCocoaErrorDomain Code=3840 "Invalid value around character 0." UserInfo={NSDebugDescription=Invalid value around character 0.} 
FAILURE

registration code snippet

Alamofire.request(.POST, url, parameters: usuario, encoding: .JSON, headers: nil).responseJSON(completionHandler: { (response) in

                if response.result.isSuccess{

                    //self.geraAlerta("Sucesso", mensagem: "Cadastro realizado com Sucesso")
                 self.populaUsuario()
                 self.performSegueWithIdentifier("cadastroTelaPrincipal", sender: self)


                }else{
                    print(response.description,"<-------")
                    self.geraAlerta("Falha", mensagem: "Não foi possível completar o cadastro, tente novamente mais tarde!")
                }
                self.btnCadastrar.userInteractionEnabled = true 
                print(response.result)
                print(response.result.value)
            })

Code in web service

@POST
@Path("/inserir")
@Consumes(MediaType.APPLICATION_JSON)
public void insereUsuario(Usuario usuario) {

    if (usuario != null) {
        try {
            usuario.setFotoByte(Util.converteToByte(usuario.getFoto()));
            usuario.setDataCadastro(new Date());

            new UsuarioDAO().inseirUsuario(usuario);
        } catch (FileNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

    }
}

Can someone please tell me how to solve this problem?

If I try to access the url directly through the browser it returns me 405